Machine for the zigzag folding of sheets

ABSTRACT

A machine is used for the zigzag folding of sheets, particularly paper sheets, in predetermined sizes. The machine has a table carrying the sheets to be folded and a carriage reciprocating above the table. A swing carried by the carriage carries a driven pair of folding rollers which are actuated in such manner that when the carriage moves forwardly one of the rollers table against the ta and when the carriage moves rearwardly the other one of the rollers presses against the table.

United States Patent 1 1 3,697,062 Mones et al. Oct. 10, 1972 [54]MACHINE FOR THE ZIGZAG 2,037,561 4/1936 Blosser et al ..270/69 X FOLDINGOF SHEETS 3,570,841 3/1971 Rettig ..270/64 2,761,678 9/1956 Conn et al...270/79 [72] Invemms' Ham Am Markweg 2,921,786 1/1960 Deichmann et a]..270/31 5601 6mm; Walter 611 799 Schulze ..270/30 Breldenhoferstrasse30, 13-5657 2,276,854 3/1942 Margadant ..270/83 Haan, both of Germany 22i D 3, 19 9 Primary Examiner-Robert W. Michell Attorney-Richards & Geier[21] Appl. No.: 881,818

[57] ABSTRACT [30] Foreign Application Priority Data A machine is usedfor the zigzag folding of sheets, particularly paper sheets, inpredetermined sizes. The I968 Germany 18 12 5570 machine has a tablecarrying the sheets to be folded and a carriage reciprocating above thetable. A swing [52] US. Cl ..270/30, 270/79 carried by the carriagecarries a driven pair of folding [51] 111i. Cl. ..B65h 29/46 rollerswhich are actuated in Such manner that when [58] Field of Search..270/30, 31, 79, 52.5, 61, 64, the carriage moves forwardly one f therollers table 270/69 against the ta and when the carriage movesrearwardly the other one of the rollers presses against the table. [56]References Cited 4 Claims, 16 Drawing Figures UNITED STATES PATENTS8,005 4/1851 Boots ..270/ 30 PATENT Enact 10 m2 SHEET 1 BF 6 INVENTORS;H. Hones M M Hone BYI AT-royLms mwml PATENTEDncT 10 I972 SHEET 3 [1F 6lll:

INVENTORS: H. Manes M4 W. Mones ATTOVLNE9$ PATENTEUucT 1 0 1972- suan u0F 6 INVENTORS! H. M00850. NOD65 BY: 1 GULJAOLAU -5- PATENTEDnm 1 I9123.697; 062 SHEET 6 OF 6 lwvliw'rtms: H. Manes m N. None;

AT ran-MESS THE ZIGZAG FOLDING OF SHEETS This invention relates to amachine for the zigzag folding of sheets, particularly paper sheets inpredetermined shapes, the machine having a table serving as a supportfor the sheet being folded.

Machines are known which fold small sheets crosswise. There are alsomachines using so-called driver sheets for folding in zigzag mannermaps, drawings or the like. The operations of these machines are verylimited. They can not be adjusted to sheets of other sizes or suchadjustment can be carried out only with great difficulty. Furthermore,it is difficult to produce on these machines precise and sharp-edgedfolds since, as is known, it is not possible to fold with sufficientsharpness paper of different thickness and types around a driven membereven if that member has a very sharp edge.

An object of the present invention is to improve prior constructions.

Another object is the provision of a machine of simple structure whichoperates completely automatically for the zigzag folding of sheets,particularly paper sheets, which can be set to any size of sheet to befolded and which will produce sharp folding edges.

Other objects of. the present invention will become apparent in thecourse of the following specification.

In the accomplishment of the objectives of the present invention it wasfound desirable to provide a carriage moving back and forth above thetable for the sheets being folded. A driven pair of folding rollerscarried by a swing is so mounted in the carriage that when the carriagemoves forward one roller presses against the table and when the carriagemoves back the other roller presses against the table.

In accordance with the present invention the drive is MACHINE FORadvantageously so constructed that the wheels actuat-,

ing the folding rollers mesh with a rack which is moved longitudinallyto provide paper entry relatively to the wheels driving the rollers.Then the rack stands still and is used for actuating the roller drivingwheels during the movement of the carriage.

Furthermore, in accordance with the present inventionthe device isadvantageously so constructed that separate racks are provided onopposite sides of the carriage, one of the racks extending below theroller driving wheels while the other rack is located above the rollerdriving wheels.

The present invention also provides an effective construction by using acrane rod drive for the tilting movement of the swing and thelongitudinal movement of the carriage.

An advantageous feature of the present invention consists in theprovision of a brake disc for at least one of the folding rollers.

Furthermore, the present invention advantageously provides pressurerollers in front of the folding rollers, at least one of the pressurerollers being movable into a raised position.

To comply with the German Industry Norm DIN824 requiring triangularfold, the present invention provides at the rear end of the table aseparate plate section which is movable up and down and which forms atriangular end portion of the incoming end of the sheet.

For this construction it is advantageouswhen in accordance with thepresent invention a ledge is provided under this section which can clampthe folded sheet end and which is movable up into the clamping position.

To produce transverse folds the present invention provides shaftslocated at the outer sides of the table and provided with foldingwheels.

The present invention provides an effective construction of the 'tableby supplying it with suction openings, known as such, for holding theincoming end of the sheet.

Finally according to the present invention it is advantageous to makethe carriage of two slide rings joined by a transverse axle and guidedon rails.

The described construction provides a completely automatically operatingmachine for the zigzag folding of sheets, particularly paper sheets. liis merely necessary to push the sheet to be folded into the machine. Thesize of the zigzag folds which are to be produced can be set asrequired. The sheet passes the pair of folding rollers carried upon aswing in a direction opposed to their direction of rotation in suchmanner that during the forward movement of the carriage one foldingroller presses against the sheet and produces a sharp folding edge,while during the return movement of the carriage the other rollerpresses against the table and also produces a sharp folding edge. Thusthe paper is advantageously folded about itself without any intermediatebody, whereby the location of the folds is attained by a preciseconformity of the movement of the paper with the movements of thereciprocating carriage. Papers of different thickness and makes can beeffectively provided with sharp folding edges. When the first paperlayer is placed the wheels driving the folding rollers mesh with thelongitudinally movable rack; when the rack stands still the rollerdriving wheels rotate upon it during the movement of the carriage. Thesegear wheels are of the same size and their pitch diameter is equal tothe roller diameter, so that the rollers rotate with a circumferentialspeed which corresponds precisely to the rolling speed of the rollersupon the table. This results in the feature that the rolling movement isexactly equal to the path of the carriage. To assure that the directionof rotation of the rollers will remain unchanged, separate racks areprovided upon the two sides of the carriage. When the carriage movesforward, the driving wheels rotate upon the rack located below them,while during the return movement the driving wheels rotate upon the racklocated above them. The longitudinal movement and the tipping movementof the swing take place advantageously through a crank rod drive. Due tothis drive, any small intermediate fold can be produced. To make a smallfold the cranks carry out only a part of a complete rotation, whereuponthey change their direction of rotation. When a dead point is reached orwhen the direction of rotation is changed, the carriage stands still anda swinging movement of the rod takes place in such manner that a rolleris raised from the table and another roller is placed upon the table.The linear movement of the carriage begins only when a roller isadequately pressed against the table. One of the rollers has. anadjustable brake disc to make certain that the operationsswinging-moving take place one after the other one to regulate theextent of pressure of the roller against the table. Pressure rollers aremounted in front of the folding rollers to make certain that the paperbeing folded will retain its location when the intermediate fold isbeing formed. Preferably when paper is inserted one of the pressurerollers can be moved into a raised position to provide free movement forone end of the paper. Since German Industry Norm DIN824 requires atriangular fold in the folding of a sheet, the table has at its rear enda table plate section which is movable separately up and down. Thissection clamps during its downward movement a triangular end section ofthe incoming end of a sheet and moves it up wardly to a small extent bymeans of a pressure ledge clamping the sheet end up to the table topsurface, so that a sharp-edged fold is produced at this section when thenext fold is being formed. In order to produce the required transversefolds in a sheet which has been subjected to intermediate folding, thesheet passes the folding wheels located upon one of the shafts at theoutlet side of the table. These folding wheels can be shifted upon theshaft, so that transverse folds can be made with any desired spacing.Suction openings provided in the table are used for holding the incomingsheet end. Suction air is turned off when the paper with intermediatefolding is transmitted to the rotating folding rollers. Since thecarriage consists of two slide rings joined by a transverse axle whichare guided in rails, a good linear shifting can be attained.Furthermore, the construction is a most advantageous one.

The invention will appear more clearly from the following detaileddescription when taken in connection with the accompanying drawingsshowing by way of example only, a preferred embodiment of the inventiveidea.

In the drawings:

FIG. 1 is a top view of a folded sheet of paper with transverse foldsand having the size of the German Industry Norm A.O.

FIG. 1a is a side view of the sheet of paper shown in FIG. 1.

FIG. 2 is a top view of the folding machine of the present invention.

FIG. 3 is a side view of the machine shown in FIG. 2.

FIG. 4 is a section through the folding rollers at the time a papersheet is inserted, a pressure roller being shown in its raised position.

FIG. 5 is a side view illustrating the wheels driving the foldingrollers.

FIG. 6 is a top view of the machine parts shown in FIG. 5.

FIG. 7 is a diagrammatic side view illustrating the entry of a sheet endwhen the pressure roller is raised.

FIG. 8 is similar to FIG. 7 and shows the operation of the pressureroller. v

FIG. 9 is similar to FIGS. 7 and 8 and shows the formation of the firstintermediate fold while the carriage is moving.

FIG. 10 is a similar diagram illustrating the formation of a secondintermediate fold.

FIG. 11 is a section along the line AB of FIG. 2 and illustrates thetable plate forming the triangular sectrons.

FIG. 12 is similar to FIG. 11 and shows the table plate as clamping theend of a paper sheet.

FIG. 13 is similar to FIGS. 11 and 12 and shows the table plate ashaving been moved slightly upwards to provide a straightening of thesheet end.

FIG. 14 is a diagram illustrating roller action upon the straightenedportion to provide a sharp fold edge; and

FIG. 15 is a diagram showing the linearly moved table when a sheet istransmitted to the folding rollers.

The folding machine shown in the drawings has a fixed table 1 and anupper table 2 movable in the direction of the arrowx shown in FIG. 3.Pairs of rails 3 and 4 are located above the table. Slide rings 6forming the carriage 5 are guided in the rails 3 and 4.

The transverse axle 7 which interconnects the slide rings 6 carries aswinging member 8 provided with axles 11 and 12 which carry foldingrollers 9 and 10 driven in opposite directions.

To provide a rotation of the folding rollers 9 and 10 in the oppositedirection, gear wheels 13 and 14 are located on one side of the rollersupon axles 11 and 12 with fixed torsion. The diameter of the foldingrollers corresponds precisely to the pitch diameter of the gear wheels13 and 14. The transverse axle 7 of the carriage 5 passes through thepoint of intersection of the line touching the pitch circles of the gearwheels 13 and 14 with the central connecting line.

Due to this arrangement the swing 8 can be moved linearly and itsswinging movement about the transverse axle 7 is provided. The center ofthe transverse axle 7 and the corresponding slide rings 6 are located sohigh above the table 1 that the swing 8 with its rollers 9 and 10 canmove due to the pushing and pulling action of the crank drive 15 or ofthe connecting rods 16 engaging the extending arms of the swing 8, themovement of the swing taking place linearly when the pushing is to theleft (FIG. 3). During this movement the folding roller 10 is pressedfirmly against the table. When the left dead point of the crank drive 15is reached, the swing 8 initially stands still and then carries out sucha swinging movement that the folding roller 10 is raised from the tableand the folding roller 9 is pressed against the table. The linear returnmovement takes place only when the roller 9 is pressed with sufficientstrength against the table.

An adjustable brake disc 18 is mounted upon the axle 11 to make certainthat the operations swingingshifting take place one after the other andto regulate the pressure of the rollers 9 and 10 against the table. Thebraking force of the disc 18 acts against the pushing and pulling forceof the crank drive 15 so that there is a lesser resistance during theswinging movement. Thus a swinging movement takes place each time thatthe direction of the linear movement of the swing is changed.

Bearing bolts 19 and 20 are fixed upon the swing 8 on both sides thereofat the intersection of the central connecting line of the gear wheels 13and 14 with the pitch circle line of the gear wheel 14. Links 21 and 22are mounted upon the bolts 19 and 20. A shaft 23 carried by the sliderings 24 connects the ends of the links 21 and 22 and is locatedopposite the bearing location.

A gear wheel 25 is fixed upon the axle l2 and is of the same size as thegear wheels 13 and 14. The gear wheel 25 meshes with an intermediategear wheel 26 carried by the link 22. A gear wheel 27 consists of twoparts 27' and 27". The part 27" meshes with the gear wheel 26 and ismounted by a free run coupling upon the shaft 23. The gear wheel part 27meshes with a bottom rack 28. The rack 28 is movable longitudinally andmeshes with a pinion 29 of a driving motor 30.

Upon the other end of the shaft 23 there is also a rotatably mountedgear wheel 31 which meshes with a top rack 32. Gear wheels 27 are of thesame size as the gear wheels l3, 14, 25 and 26.

Due to this arrangement of the driving wheels and the racks the foldingrollers 9 and 10 do not change their direction of rotation during theforward and return movements of the carriage 5. During the forwardmovement of the carriage 5 the gear wheel 27 engages and rotates uponthe rack 28 and drives the folding roller 10 through the intermediategear wheel 26 and the gear wheel 25. The gear wheel 14 of the foldingroller 10 meshes with the gear wheel 13 of the folding roller 9 and thusrotates the latter. During this movement the gear wheel 27 upon theshaft 23 runs empty.

During the return movement of the carriage the rotatably mounted gearwheel 27' turns upon the rack 28 but the shaft 23 and the gear wheel 27"do not partermediate wheel 26 and the gear wheels 25, 14 and 13 ticipatein this movement. The gear wheel 31 rotates upon the rack 32 and drivesthe folding rollers 9 and 10 through the shaft 23, the gear wheel 27",the intermediate wheel 26, the gear wheel 25 and the gear wheels 14 and13, whereby the folding rollers retain their direction of rotation.

The circumferential rotation imparted to the folding rollers 9 and 10 isexactly equal to the speed with which they turn upon the table.

Pressure rollers 34 and 35 are carried by swinging arms 33 and arelocated in front of the folding rollers 9 and 10. The pressure roller 34can be moved to a raised position by a magnet 36 fixed to the swing 8.

The table 1 is provided upon the rear end with a plate section 37movable up and down. A pressure link 39 which is actuated by a magnet 38cooperates with the plate section 37.

To provide transverse folds in a sheet being folded, shafts 41 providedwith folding wheels 40 are located adjacent the table 1. One wheel 40has a triangular rib 40' and the wheel belonging thereto has acorresponding triangular groove 40 (FIG. 2).

The operation of the described machine is as follows:

Let it be assumed that a paper sheet is to be folded the size of whichis that of the German Industry Norm DINAO (FIG. 1 The sheet is placedupon the supporting table surface 42 (FIG. 3) so that its narrow sideextends parallel to the axles of the folding rollers. The sheet isshifted in the direction perpendicular to the axles 11 and 12 and passesthe light gates 43 which establish a' specific folding program forsheets of specific size. Then the paper sheet is guided by theconducting sheets 44 and 45 until the narrow edge of the paper sheetreaches the point of contact of the folding rollers 9 and 10. Furthershifting will bend the paper so that it will press against the key 46 ofthe microswitch 46 and thereby start the machine (FIG. 4). Thisarrangement makes certain that the mechanisms will start their motorsonly when the paper edge is definately located at the line joining thefolding rollers and when the paper is subjected to a certain pushingpressure, so that when the folding rollers begin to rotate they willimmediately move the paper sheet. The microswitch 46 will switch on themagnet 26 so that the pressure roller 34 is moved into its raisedposition. Furthermore, the microswitch 46 switches on the irreversiblemotor 30,

the pinion 29 of which meshes with the rack 28 and shifts it in thedirection of the arrow y (FIG. 6). The

rent emerging from the nozzles 47 (FIG. 4) and will be' guided at thesame time toward the surface of the table. The folding rollers 9 and 10which at that time do not move longitudinally, transport by theirrotation the paper sheet B further across the table until the front edgeof the sheet reaches the light gates 48 (FIG. 7). This will stop themotor 30 which drives the folding rollers 9 and 10 through the rack 28.

If thicker paper sheets are used, the safe guiding of the sheets may beassured by providing a guiding strip 49 shown by broken lines in FIG. 4,which swings back after the end of the sheet has reached the tablesurface. I

The pressure roller 34 also facilitates the proper position of the papersheet. Then the crank drive starts and causes a forward movement of thecarriage 5 in the course of which the paper sheet B forms a loop whichis frictionally pressed by the folding roller 10, as shown in FIGS. 8and 9. After reaching the end position, which is the dead point positionof the cranks 15, the swing 8 is swung about the transverse axle 7during further crank movement, whereby the folding roller 9 moves intoengagement with the table surface, while the other roller 10 is raisedfrom this surface, as shown in FIG. 10.

Then the procedure of loop forming and sharply shaping the fold isrepeated in the same manner as already described. The pressure rollerskeep during this folding procedure the sheet firmly upon the table andprevent it from shifting.

It is possible to provide any other smaller paper fold, in which casethe cranks will carry out only a part of a complete rotation and willchange their direction of rotation.

The triangle, which is required by the German Industry Norm DIN824 isfolded according to the same procedure. When the first paper sheet ismoved in, the angle-shaping plate 37 is located in its upper position(FIG. 11). After the first paper sheet is placed, the plate 37 movesdownwardly and bends a triangular portion B with light roundings (FIG.12). Then the pressure ledge 39 which is horizontally movable under theplate 37 and which is provided with a rubber strip 50, will be actuatedby the magnet 38 and will press the bent triangular end portion B of thesheet against a smooth front wall 1 of the table 1. Then the plate 37 ismoved upward up to the table surface. This movement will raise the paperso that it will form a bend B" above the table surface (FIG. 13).

When the next paper sheet arrives this bend will be shifted by thefolding rollers from right to left and it changes into a sharp fold bentagainst itself, as shown in FIG. 14. After the sheet B has been providedwith an intermediate fold and with a bent triangle, the machine partswhich carried out these operations will move back to their initialpositions. The upper table 2 is shifted in the direction of the arrow x(F. 15) toward the rotary folding rollers 40 and takes along with it thelongitudionally folded paper sheet B, which is held upon the table bysuction openings 51. Then the paper sheet is engaged by the rollers 40.During this operation the plate 37 is moved downwardly to such an extentthat it provides free movement for the upper table 2 and the triangularsheet portion B. Due to the sharp folding edge of the sheet portion Band with the assistance of plates 52 the triangular sheet portion B willbe bent over the sheet B. Suction air is switched off; when the papersheet is taken over by the rollers 40 it will be pressed by the rollersand due to the projections and grooves provided upon the rollers (FIG.2), it will receive two transverse folds B' located on opposite sides(FIG. la), so that the separate sections can be conveniently bent byhand.

We claim:

1. Machine for the zigzag folding of paper sheets and the like,comprising a table adapted to carry a paper sheet, a carriage, a crankdrive connected with said carriage for moving said carriage forwards andbackwards above said table, a swing mounted in said carriage andconnected with said crank drive, two folding rollers carried by saidswing, two pressure rollers, arms connecting said pressure rollers withsaid folding rollers, means moving at least one of said pressure rollersinto a raised position, two racks located on opposite sides of saidcarriage, and means connected with said racks and said folding rollersand actuating said folding rollers to press one of said folding rollersagainst a paper sheet upon said table during the forward movement ofsaid carriage and to press the other one of said folding rollers againstthe paper sheet upon said table during the backward movement of saidcarriage.

2. Machine in accordance with claim 1, comprising braking meansconnected with at least one folding roller and acting upon said crankdrive.

3. Machine in accordance with claim 1, comprising a plate located closeto an end of said table and movable relatively to said end to bendangularly a paper sheet portion extending beyond said end.

4. Machine in accordance with claim 3, comprising a pressure ledgelocated adjacent said plate and means moving said ledge into engagementwith said bent paper sheet portion to raise it above the table.

1. Machine for the zigzag folding of paper sheets and the like,comprising a table adapted to carry a paper sheet, a carriage, a crankdrive connected with said carriage for moving said carriage forwards andbackwards above said table, a swing mounted in said carriage andconnected with said crank drive, two folding rollers carried by saidswing, two pressure rollers, arms connecting said pressure rollers withsaid folding rollers, means moving at least one of said pressure rollersinto a raised position, two racks located on opposite sides of saidcarriage, and means connected with said racks and said folding rollersand actuating said folding rollers to press one of said folding rollersagainst a paper sheet upon said table during the forward movement ofsaid carriage and to press the other one of said folding rollers againstthe paper sheet upon said table during the backward movement of saidcarriage.
 2. Machine in accordance with claim 1, comprising brakingmeans connected with at least one folding roller and acting upon saidcrank drive.
 3. Machine in accordance with claim 1, comprising a platelocated close to an end of said table and movable relatively to said endto bend angularly a paper sheet portion extending beyond said end. 4.Machine in accordance with claim 3, comprising a pressure ledge locatedadjacent said plate and means moving said ledge into engagement withsaid bent paper sheet portion to raise it above the table.